PROJ00151

• Contract/PO #: C153449
• Contractor Name: North Poudre Irrigation Company
• Contract Type: Loan
• Water District: 3
• County: Larimer
• Bill Number: HB 85-1042
• Loan Projects - Doc Type: Feasibility Study

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CHAPTER V - PLAN OF DEVELOPMENT

EXISTING FACILITIES

Reservoir No. 15 Dam and Spillway was originally constructed in
about the year 1909. It is an homogenous earthfill dam, 49 feet
high at the maximum section, and 3,700 feet long. A 50 feet wide
emergency spillway overflow was excavated at the right abutment.
The outlet works consists of a cast-in-place concrete arch 3 feet
wide and 4 feet high. The upstream portion and gate well ~f this
outlet works was reconstructed in 1948 and 1949; however the down-
stream portion of the outlet is of the original 1909 construction.

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The upstream slope of the embankment was originally constructed to
a 3:1 slope. Excessive erosion has occured in the upstream slope
resulting in over steepening of the face to nearly 1:1 slope. This
has occured due to displacement of fill material from below the
riprap face.

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Upon full filling, excessive seepage has been noted below the toe
of the dam, including boggy areas several hundred feet below the
toe of the dam.

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For the last few years, the deterioration of these structures has been
a concern to both the Owner and the Colorado State Engineer. The
decreed high waterline to Reservoir No. 15 is to gage rod 42.2 feet.
The Colorado State Engineer's Office has issued a restriction upon
this reservoir to gage rod 40.0 feet.

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It is of concern to the Owner's that were this facility not to be
repaired, increaseu restrictions may be placed on this facility
resulting ill eventual loss of the use and water rights associated
therein.

PROPOSED IMPROVEMENTS

In order to restore the facility to 100% utilization, it 1S necessary
to reconstruct the embankment front face including placement of add-
itional fill material, filter gravel, and riprap. In addition, a

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